Trap-door opener.



, UNITED STATES Patented' June v14, 1904.

PATENT OFFICE.

if TRAP-Doon OPENER. f'

SPECIFICATION forming part of Letters Patent No.77622741, dated une 14,' 19014 Application filed February 18,1994. Serial No. 194,132. (No model.)

To all whom it may concern:

Be it known that I, CHRISTIAN HANSEN. Moos, a citizen lof the United States, and a resident of Stillwater, in the county of Washing ton and State of Minnesota, have invented a new and Improved Trap -Door Opener, of which the following is a full, clear, and exact description. r f

4This invention relates to means for automatically opening ,a heavy trap-door-that guards an opening in a Hoor, and has for its object to provide novel features of construction for a trap-door opener that are extremely simple, practical, and inexpensive, take up but little room, do not obstruct the door-opening,

.afford means for counterbalancing doors of different weight that are provided with the improvement, and also permit'the graduation of the liftingpower, so that the door will remain closed until started to open by a slight manual effort. A

The invention consists in the novel construction and combination of the several parts` as will be hereinafter fully set forth, and pointed out in the claim. f

Reference is to be had to the accompanying p drawings, forming a part of this specification,

in which similar characters of reference indicate corresponding parts in all the gures.

Figure 1 is a transverse sectional view of a Hoor at a door-opening, a vertical wall adjacent to the door-opening, a longitudinal sectional viewof a trap-door hinged to adapt it to open or close the door-opening, and a side view of the Improved door-closing device con? nected with the floor-timbers 'and with the door, holding the latter in closed condition.

Fig. 2 is a similar view to-Figfl, but showing the door open and held in a vertical position; and Fig. 3 isa front view of. the door-'closer and of the door held opened thereby seen inv direction of the arrow fa in Fig. 2.

In the drawings, 5 represents sectionally a floor in part supported horizontally by the' 7, and 10 indicates hinges secured upon the Iioor andthe upper side of the door at the side edge a of the door-opening, thus adapting a rocking movement' of the door to open or 'close said door-opening, the completedepression` of the door serving to lill vthe opening 7 and dispose the door in the same plane with,

The improved door-opening device cornprises the following details: A metal bar is bent or formed to produce an angular corner at b and afford two arms 11 12, disposed substantially at right angles to each other.' A bracketiplate 13 is secured upon the floor or a joist 6 below and near the hinged edge of the door 9, said plate supporting by a pivot at its lower end the angularly-diverged arms 11 12 at their corner whereby the arm 12 may assume an upright position near the door 9 when said door is in opened adjustment.

The bracket-plate 13 and arm 12, held to rock thereon, are placed near the transverse center of the opening 7 and the door 9. Upon the free end of the arm 12 a roller cis pivoted, and upon the free end of the arm 11 a hook d is preferably-formed.

On the side of the door 9 which is lowermost when the door is closed a wearLplate 14. is secured, that extends from the hinged edge of the door toward the opposite edge. The

,wear-plate 14: is located at the transverse center of the door 9, so that the rollerc may contact therewith, and obviously the roller 'will traverse the wear-plate longitudinally if jheld in contact therewith and the door is rocked upon its hinges.

A weight 1 5 of sufficient heft to nearly lcounterbalance the weight of the door 9 is furnished and is hung from a link-rod 16,

whereon a hook @is formed, that engages the hook d, or the hook @may be closed to pro- IOO ally, so that when the door is closed it will remain so adjusted until it is desired to raise it and remove it from the opening 7 At any time when it is necessary to open the trap-door 9 the ring g is taken hold of and a slight lifting pull is applied thereto, which will start the rocking movement of the door upwardly and enable the gravity ofthe weight-block l to pull the arm 1l downward and the arm 12 upward, thus pressing the roller 0 against the wear-plate 14, over which said roller travels. The door 9 is thus automatically opened and when rocked into a vertical position may be arrested from rocking further toward the partition 8 by the abutment z, that may be formed or secured on the wall 8 for contact with the door.

It will be seen that the device may be applied upon trap-doors having different weight and area, as the weight-block 15k may be exchanged for one of proper heft to suit the gravity of the door, so that the improvement may be generally applied for counteraeting the gravity of a hinged trap-door and automatically raising said door after it has been started by a slight pull.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- A trap-door opener, comprising a substantially dat bar, bent near its longitudinal center, producing two arms that diverge essentially at a right angle from each other and are disposed in the same vertical plane in service, a bracket-plate depending from a licorjoist near the trap-opening in the Hoor` a hinged door which when closed will lill the opening, a pivot -support for the integral arms which holds them free to rock on thel bracket-plate at the junction of said arms, a roller on one arm which makes contact with a wear-plate on the normally lower side oi the door, a link-rod hooked upon the 'free end of the other arm, a weight on the rod that nearly counterbalances the weight ot' the door when it is closed, means for raising the door manually to give it an upward impulse, and an abutment whereon the door will have contact when it is fully opened.

In testimony whereolc I have signed my name to this speciiication in the presence of two subscribing witnesses.

CHRISTIAN HANSEN MOOS.

Witnesses:

D. A. CoNNoRs, FRED S. FOSTER. 

